1. Field of the Invention
The present invention relates to systems and methods for serving advertisements and related content to users in a distributed, content-based system.
2. Description of the Related Art
Various types of ad placement systems exist for displaying targeted advertisements on web pages. One type of system allows business entities (advertisers) to associate their respective ads with specific keywords, which may include phrases. When a user submits a search query to an Internet search engine, the ad or ads associated with the keyword or keywords entered by the user are displayed on the resulting search results page—typically under a heading such as “sponsored links” or “sponsored results.” The display position of each such ad relative to other ads, and the amount paid by the corresponding advertiser if the ad is clicked on by a user, is typically dictated by a keyword bid amount specified by the advertiser. Typically, the ads of each advertiser are displayed on a variety of different independent web sites through a process known generally as syndication.
Another type of ad placement system operates by selecting ads to display on relatively static web pages by performing content-based analyses of such pages. For example, Google's AdSense program allows web site operators to configure selected pages of their respective web sites to display or “host” ads served by a remote ad server. To select appropriate ads to display on a given page, a crawler program is typically used to analyze the textual content of the page, and to attempt to match the page's content to relevant ads.
Online advertising has seen tremendous growth, and is now a multi-billion dollar industry. An online ad typically is linked to a web site that provides products or services for purchase. Many online businesses are reputable and provide excellent service and support. Others, however, may provide less than desirable results. Given the large number of online advertisers, it is often difficult for a user to know if an advertiser is reputable.